Concrete metal construction.



PATENTED MAR. 5, 1907.

E. PLAD. CONCRETE METAL CONSTRUCTION APPLIOATION FILED D30. 31, 1904.

2 SHEETS-SHEET 1 WNW 4 I. WHH

INVENTOH WITNESSES.

m 1 M pm d r a w d E No. 845,938. PATENTED MAR. 5, 1907. E. FLAD.

CONCRETE METAL CONSTRUCTION.

APPLIUATION FILED DEU. 31,1904.

2 SHEETS-SHEET 2.

Fig.4.. Fig.5.

WITIVESSES: nvvuvm/r wvjgg d ad. it m EDWARD FLAD, OF ST. LOUIS, MISSOURI.

CONCRETE METAL CONSTRUCTION.

Specification of Letters Patent.

ratenteol Manh 5, 1907.

Application filed December 31, 1904. Serial No. 239.180-

To (LN whont H 11w, concern..-

Be it known. that I, EDWARD Fran, a citizen of the UnitcdSLates. residing at the city of Louis, State of Missouri, have invented a certain new and useful Concrete and Metal Construction, of which the following is such a full, clear, and exact description as will enable any one skilled in the art to which it ap crtains to make and use the same, reference )Gillg had to the accompanying drawings, forming part of this specification.

My invention relates to a concrete and metal construction, and more nirticularl to that form of concrete and metal construction in which a body of concrete or other similar plastic material has embedded therein one or more metal bars provided with pro- 'cctions which increase the grip between the er and the surrounding material. In order that such projections may be effective to in crease the gri between the bar and the ma- ;terial and at the same time prevent tendency to split the material, it is necessary that any plane tangent to the bcaringdace of the projcction shall make an angle with a plane at right angles to the axis of the bar not greater than the angle of repose between the matcrial of the bar and the surrounding plastic material.

I am aware that concrete and metal constructions have been heretofore us d in which the metal bars were of the general description above referred to. In all such cases, however, as far as I am aware, the projections have been arranged on the bar in one of two ways: First, theyhave been so arranged that they will not be cut by all planes perpendicular to the axis of the bar. Colisequently the cross-sectional area of the com bincd bar and projections will not be uniform throughoutthclengthof the'bar. Second, the

pro ections have been as wide or wider than the space between the projections. In either case the metal is not used to the greatest a.ivantage, in the first instance because the projections form no useful part of the bar in resisting tensile or compressive strain and in the second instance because much more material is used in the projections than is necessarv, as projections shouH be of substantia y the same strength as the interlocking concrete projections.

j The object of my invention is Io so arrange the projections on the bar that they can be placed farther apart than their width andat the same time be cut by all planes perpendicular to the axis of the bar, thus using the metal to the greatest advantage.

I accomplish the above objects by arranging the projection or projections around the bar in the form of a spiral, either singly or doubly, according to circumstances, as will be hereinafter more fully des'cribed.

In the accompanyingdrawings, which illustrate a construction made in accordance with my invention, Figure 1 is a sectional view, on a reduced scale, showing the use of my construction in an arch for a. ln'idge or the like. Fig. 2 is a section on the line 2 2 of Fig. 1. Fig. 3 is a side view of a round bar made in accordance with my invention. Fi 4 is a diagram showing the developed suriiice of a bar having the projection arranged in the form of a single spiral. Fig. 5 is a diagram showing the developed surface of a bar having the projections arranged in the form of a double spiral. Fig. 6 is an isometric projection of a square. l ar provided with projections in the form of a single spiral, and Fi 7 is an isometric projection of a square bar having the projections formed in a double spiral.

Like marks of reference refer to similar parts in the several views of the drawings.

10 represents the body oi concrete in which the bars are embedded. in the present instance this body of concrete is shown in the form of an arch for supporting a bridge or other structure. The bars 11 are preferably square in cross-section and they are arranged within the concrete in the usual manner so as to resist either tensile or compressivc'strain. The bars I] are provided with a projection or set of projections 12, forming a spiral. 'lliis spiral may be single, as shown in Fig. 6 and developed in Fig. 4, or it may be double, as shown in Fig. 7 and developed in Fig. 5. The single 'lorm shown in Figs. 4 and 6 may be used in case the spiral is made continuous.

Such a. continuous spiral is also shown in Fig. 3, in which form, however, a round bar 14 is used in place of the square bar 11. It will be evident that any plane perpendicular to the axis of lhe bar will cut this spiral projection, and eonsmpu'utly that the spiral piojcction will form an cilcrtivc part of the bar to resist both tensile and compressive strain. Such a plane is shown on the line the angle of repose, said tions being arran ed to perpendicular to t e axis of the bar. j l 9. lIn-aooncrete and metal construction, a body of concrete having a metal bar embedded therein, said bar being circular in crosssection, and being provided with a projection or projections the bearing-surfaces of which form with a plane at right angles to the axis of the bar an angle not greater than the angle E of repose, said projection or projections being I arranged to be cut by all planes perpendicnj lar to the axis of the bar. a 10. In a concrete and metal construction, a body of concrete having a metal bar e nbedi ded therein, said bar being curviliner in 5 cross-section, and. being provided with a l spiral projection or projections, the bearingsurfaces of said projection or projections j projection or projece cut by all planes l axis of the bar plane at right angles to the an angle not greater than the angle of repose.

11. In a concrete and metal construction, a body of concrete having a metalibar embedded therein, said bar being circular in crosssection, and being provided with a spiral proforming with a j j ection or projections, the bearing-surfaces of said projection or projections forming with a plane at right angles to the axis of the bar an angle not greater than the angle of repose.

In testimony whereof I have hereunto set my hand and allixed my seal in the presence of the two subscribing Witnesses.

EDWARD FLAD. [1,. s.]

Witnesses:

BicNNE'r'rn PIKE, W. A. ALEXANDER. 

